Broaching machine



May 31, 1955 c. A. Bor-:HM ETAL ROACHING MACHINE 5 Sheets-Sheet 1 Filed July 21, 1951 May 3l, 1955 Filed July 2l, 1951 C. A. BOEHM ET AL BROACHING MACHINE 5 Sheets-Sheet 2 Fi g Z INVENToRs. om oEHM BY EMERY c, Ram/m TTORNEYS.

May 3l, 1955 c. A. BoEHM ETAL 2,709,395

BRoAcHING MACHINE Filed July 2l, 1951 5 Sheets-Sheet 3 l ATTORNEYS.

May 3L 1955 c. A. BOEHM ET AL 2,709,395

BROACHING MACHINE Filed July 2l, 1951 5 Sheets-Sheet 5 l] TTORNE YS nite nnoncnnvo MACHINE Carl A. Boehm and Emery C. Raehrs, assignors to The Cincinnati Milling cinnati, Ohio, a corporation of Ghia Application `luly 21, 1951, Serial No. 237,902 6 Claims. (Cl. 90 33) Cincinnati, Ohio, Machine Co., Cin- This invention relates to improvements in broaching machines and has particular reference to improvements in suriace broaching machines.

One of the objects of the present invention is the provision of novei and improved mechanism for controlling the presentation of a work piece to a broaching member and maintenance of the work piece improper position during performance of the broaching operation.

A further object of the present invention is the provision in connection with a duplex type of broaching machine of improved means for effecting selective presentation of work pieces to the broaching devices in connection with novel and improved cycle controls for the sequential operation of the several parts of the machine.

An additional object is the provision of an improved type of locking mechanism positively to secure the work in position during performance of the breaching operation.

Other objects and advantages of the present invention should be readily apparent by reference to the following Figure 3 is a vertical section on the line 3 3 of Figure l.

Figure is a horizontal section on the line 4 4 of Figure 2.

Figure 5 is an enlarged fragmentary front elevation of the m chine with a portion of the bed broken away to expose the contained operating mechanism.

Figure 6 is a fragmentary plan view as on the plane 6 5 indicated inFigure 2, and

Figure 7 is a diagrammatic view illustrating the hydraulic circuits of the machine and controls therefor.

In the drawings, in which similar characters o f reference denote corresponding parts throughout the several views, the numeral 10 designates the base 0f the machine having a bed portion 11 and an upstanding column portion 12. The column portion i?. is provided with the sets of ways 13 and 14 for the vertically movable rams 15 and 16 hereinafter referred to respectively as the left hand and right hand rams. These rams are provided with suitable breaching tools as indicated at 17 for operation on the work pieces to be formed. The left hand ram 15 has connected thereto piston rod 18 carrying piston 19 movable in cylinder 2%. Correspondingly, the right hand ram 15 has secured thereto the piston rod y21 carrying piston 22 vertically movable in cylinder 23, the cylinders 2i) and 2.3 being suitably located within and secured to the base it) of the machine.

States Patent N' 2,739,395 Patented May 3l, i955 The bed 11 is provided with the left hand set of ways 24 for the work holding carriage or table 25 and the right hand set of ways 26 for the right hand work holding carriage or table 27. Each of these carriages is provided with the adjustable stop or limit screws 2d cooperating with the abutments 29 on the bed for limiting the movement of the respective work carriages in the direction of the broaching rams. The advance and the retracting movement of the carriage is under control of a piston 30 movable in cylinder 31 carried by the bed at one side of the column 12 while the advance and retraction of the work table 27 is controlled by piston 32 movable in cylinder 33 carried by the bed at the opposite side of the column 12. Piston 32 is provided with the piston rod 34 coupled by link 36 with the intermediately pivoted lever 37 secured to the bed and having its other end pivoted to the slide block 38 reciprocably mounted on the guides 39.

Pivoted between the lugs or ears di) on the slide block 33 is a link 41 secured by the pivot pin Li2 to the overlapping ends of the toggle levers or links i3 and d4. The relationship of these parts is such that when the block 38 is in its forward position, as indicated in Figure 3, and at the upper right hand portion of Figure 6, the toggle arms 43 and 44 will be aligned one with the other in a dead center relationship while the link il extends at right angles to the combined toggle thus provided. The link 41 consequently holds pin 42 on center as respects the centers of the pivots 45 and 46. The pivot 45 connects the forward end of the toggle arm i2 to a depending portion of the work carriage while the pivot 46 is secured to the bed i1. Consequently, with the parts in the position shown, in Figure 3, the table will be locked in its extreme forward position with the abutments 2S and 29 interengaged so that a work piece carried by the table or carriage will be held in proper relationship to the broach 17.

On the other hand, when the slide block 38 is moved rearwardly, member 41 will draw the pin 42 downwardly and rearwardly, the links or levers 43 and 44 swinging about their respective pivots into the dotted line relationship, indicated in Figure 3, causing an unlocking and retraction of the carriage 27.

A corresponding set of linkage elements interconnect the rod 34 of piston 3i) with the carriage 25 and as the parts in question are identical in structure, they have been identified by corresponding reference characters throughout the drawings as respects the parts just described. This latter piston rod carries the direction controi arm 35.

It will be understood, as has been indicated for simplicity in Figure 7, that each carriage is individually operated, locked and unlocked by its respective piston and capable of independent control. However, to insure proper relative timing under all operating conditions and a corresponding but opposite movement of the respective work carriages, the slide blocks 38 have been shown as formed with the transverse ways such as i7 receiving slides or anti-friction rollers 48 at the opposite ends of lever 49 intermediately pivoted at 50 to the bed of the machine. By this interconnection a balancing of power movements and correspondence of timing to the opposite directional movements of the respective carriages is effected.

The cyclic operation and control of thev various parts of the machine will be best understood by reference to Figure 7. As there indicated, there is employed a first high pressure pump unit 51 taking actuating medium from the sump or tank 52 and discharging same by way of line 53 to high pressure relief valve Sd which may be set, for example, at 800 pounds to the square inch and having a return line 55.

In Figure 7 the right hand brooch ram 16 is indicated as moving downward or toward the bottom of the sheet and the left hand ram as moving upward or toward the to;l of the sheet, and the various control valve elements are indicated in the respective positions which they occupy during this part of the machine cycle. The high pressure actuating medium is discharged from the pressure valve 54 by way of conduit 56, groove 57 of the manually actuable start, stop or reverse valve 5S, groove 59 ot the ram direction valve 60, conduit 61 and groove 62 of the right hand ram control valve 63 and conduit 64 to the top of the cylinder 23, thus forcing piston 22 and its associate ram 16 downward for performance of a breaching operation. At the same time the lower or exhaust end of the cylinder 23 is connected by conduit 65, groove 66 oiD the right hand ram valve 63, conduit 67, groove 68 of the left hand or ram valve 69 and conduit 70 to the bottom of cylinder 20, reacting on piston 19 to raise the ram 15 during its return non-cutting stroke. The upper or exhaust end of cylinder is coupled by conduit 71, groove 72 of the left hand ram valve 69, conduit 73, groove 74 of the ram direction valve 60, conduit 75, groove 76 of the valve 58, conduit 77, groove 78 of valve 54 to the reservoir return conduit 55. ln this manner, the high pressure actuating medium reacts directly on the cylinder alecting the breaching operation and indirectly by the way of exhaust from this cylinder into the opposite cylinder for retraction or upward movement of its piston and thus the associate broaching tool. At this time the piston 32 is in its retracted position, reacting through the associate block 38 to maintain in straightened out or locked position the toggle mechanism and thus carriage 27, while the piston is oppositely disposed so that table 25 is retracted as respects the broach ram 15 for removal of a finished work piece and mounting in operative position of the work piece to be subsequently broached.

As the ram 16 reaches the limit of its desired operative stroke an adjustable dog 79 on the ram engages head S0 of valve S1, moving this valve to its left hand position as determined by the detent 82.

Prior to this actuation, the valve, as shown in Figure 7, has been in its right hand position. When in this position, the pilot circuit pump 33 receiving its lluid from the reservoir 52 has been maintaining pilot pressure in the conduit 3d through groove 85 of valve 81 j and conduit 36 to maintain pressure in the lett hand chamber of the bushing 87 of valve 63 while the opposite end of the bushing is coupled by conduit 88 and groove 89 by valve S1 to the pilot circuit return conduit 9?, and the valve 63 is held in its right hand position.

However, on thc dog elected shifting of the pilot valve 81 the right hand ram valve 63 will now be reversed or moved to the left, connecting the high pressure conduit 61 with 67, and in the event that piston 19 of ram 15 has not completed its stroke, the pressure fluid will be coupled through valve 69 with conduit 70 accentuating the upward movement of this ram. Upon completion of upward stroke of rarn 15 its lower dog 91 will engage and shift pilot valve 92 from its existing right hand position to a left hand position. This will couple pilot pressure conduit 84 with conduit 493, introducing pressure against the left hand end'of valve 69 ,'hile coupling conduit 94 from the right hand end of the valve with return conduit so that valve 69 is now shifted to its right hand position. This movement coupled 67 which is now a pressure conduit with 95 which due to shifting of valve 63 is now connected with conduit 96. Conduit 95 has a branch 97 extending to the low pressure side 98 of the pressure relief valve which, as adjusted, maintains a suitable pressure such as 300 pounds to the square inch in this conduit system.

Ram 16 is provided with an additional adjustable dog 99 effective at its limit of downward movement to trip switch 100 in the control circuit 101 for solenoid 102y of valve 103 moving this valve to the right against the action of spring 104. Movement of valve 103 to the right couples pilot pressure circuit or conduit S4 through conduit 105 to the terminal piston portion of valve 106, moving this valve to the right to connect 96 with 107 which has a branch 108 connected to the lower end of cylinder 33 and a branch 109 connected to the upper end of cylinder 31. This introduces pressure against the underside of piston 32 to raise the same, thus shifting 38 downwardly as viewed in Figure 7 or to the left as viewed in Figure 3, breaking the toggle joint to unlock and effecting retraction of the work holder 27. At the same time reaction of the pressure on piston 30 will move the left hand member 38 upwardly as viewed in Figures 4 and 7 to react through its coupled toggle mechanism to move the work holder 2S into forward or operative position for engagement by the breaching tool on ram 15 and locking it in this position. As before mentioned, synchronism in movement of these parts may be effected as by the interconnecting lever 49 shown in Figure 4. As the parts move into locking position, arm 35 shifted by piston 30 will engage collar 110 on the stem of valve 111, moving this valve downwardly as viewed in Figure 7 to connect pilot pressure conduit 84, with conduit 113 for moving valve 60 to the right. At the same time, conduit 114 coupled to react on the right hand end of the valve 60 is connected to the reservoir conduit 90, relieving the previous pressure condition which had moved and held the valve 60 to the left. It will be noted that this operation cannot take place until after proper positioning of both the right hand ram control valve 63' and the left hand valve control valve 69 and after the work table 25 has been moved into and clamped in operative position.

Movement of the ram direction valve to the right will shut oft the pressure connection to 61 and couple pressure conduit 115 with conduit 116 by way of groove 72 of valve 69 when the latter is in its right hand position. As has been previously described, conduit 71 is connected to the upper end of cylinder 20 of the piston for broach ram 15 so that the pressure reaction will impart a breaching movement to the ram 15. At this time conduit '70 from the lower end of cylinder 20 is coupled by way of valve 69 with conduit 117 and by way of valve 63 in itsleft hand position to conduit 65 extending to the lower end of cylinder 23 reacting on piston 22 to raise the ram 16.

At the completion of the strokes of the respective rams, the actuation of the parts will be elected as before, the ram 16 moving the dog 118, returning the valve 81 to the right hand position shown in Figure 7 while the dog 119 0u ram 15 will move the valve 92 to its right hand position as also shown in Figure 7 at the completion of the ram stroke. lt will be noted that ram 15 is provided with an additional dog adapted to actuate the switch 121 which is connected to the control circuit 101 in parallel with the switch 100. Consequently, actuation of either switch 100 or 121 by downward movement of its controlling ram will cause energization of solenoid 102 to move the valve 103 to the right, causing hydraulic actuation of valve 106 as long as a controlling dog is in engagement with either switch or 121. Initiation of a cycle of ram movements, however, will release these control switches so that valve 106 is normally actuated by spring 122 to impound the hydraulic lluid in the table actuating cylinders, thus locking the parts against movement during the breaching operation., From the position of the several valve mechanisms shown in Figure 7, prior to the tiring of valve 60 for etlecting the downward movement of the ram 16 as shown in Figure 7, the valve position was at the right instead of the left, pressure being connected from 115,116, 95 to 123 so that in this instance when the valve 106 was temporarily shifted to its right hand: position, pressure line 123 would have been coupled to 108 and thus to the upper end of cylinder 31, causing the respective movements of the control pistons and work tablesv or carriages as shown in said Figure 7.

To prevent improper starting of the machine there has been provided in the starter circuit a safety switch 124 normally closed but shiftable by movement of valve 58 toward the left or starting position to interrupt the Starter circuit. This necessitates that the valve 58 be in the stop position before the power circuit controlling thel electric motors for operation of the machine can ne energized.

Additionally, there has been provided in the master stop power control circuit 125, the pair of normally closed limit switches 126 and 127 disposed in parallel. Individual opening of one or the other of these switches will have no eiect on the circuit 125, but if both of the switches are open at the same time the master stop switch 128 will be opened to deenergize the drive motors of the machine. The switch 126 is disposed in position to be contacted by stem 127 of the carriage control valve 106 so that this switch is opened, interrupting one branch of the control circuit at any time when the valve has been moved to position to connect hydraulic medium for shifting of the Work carriages. It will be understood that in normal operation this position of the valve exists for a short time only during the period when either' of the rams is in its lowerrnost position so that switch 196 or 121 is activated and that as soon as the related ram has moved upward,

disengaging the operated switch the valve is intended to return under the inuence of spring 122 to its circuit interrupting or blocking position. However, should the valve fail to move, switch 126 will remain in open position. The additional switch 127 has a portion projecting into the path of movementof dog 129 intermediately located on ram 15 or 16. As a result of the positioning of this dog, during each intermediate portion of the ram stroke the switch 127 will be temporarily opened. lf switch 126 is closed, this will have no eiect on the master switch, but if for any reason switch 126 is in open position during the period when the dog 129 actuates switch 127 both branches of the control circuit 12S will be interrupted, causing actuation of the master stop switch 12S and thus complete stoppage of operation of the machine.

From the foregoing description it will be noted that there has been provided a novel and improved form of mechanism which in its simplest form comprises a reciprocable work holding member or carriage and an improved toggle lock mechanism alternatively eiective to lock the work holding carriage in position for performance of the tooling or work forming operation, or actuable to effect a definite and positive retraction of the work carriage with respect to the tooling means.

In the particular embodiment shown, this mechanism has been embodied in two alternatively available and employable carriage mechanisms mounted for opposite actuation by the medium of interconnected power means and that there has additionally been provided a mechanical coupling between the parts for insuring and maintaining their correspondingly timed opposite actuations.

t will further be noted that there has been provided a novel and improved interlock control mechanism including sequentially actuabie valve means for determination of the respective movements of the work holders or carriages and of the tool bearing rams in which the control elements are so related as to maintain a definite continuous cycle operation of the parts with diversions and alternate couplings and utilization of the power source or sources in such manner that improper or out of step operations of the tool actuating means and of the work holding means are prevented. Furthermore, various safety devices have been incorporated in the control mechanism such that one shiftable element must have completed its movement before movement of a sequentially effective part is possible, while other control devices are provided to stop. operation of the machine in the event" of improper functioning of the parts.

What is claimed is: l. In a duplex broaching machine embodying a bed and a column rising from the bed having independent.

'2 ram portion of the column, a toggle mechanism individual to each of the carriages having a portion pivoted to its associate carriage and a second portion pivoted to the bed, an individual hydraulic motor coupled with each toggle mechanism. for controlling the position of the toggle mechanism and thus of the associated carriage, means for effecting corresponding opposite actuations of the motormechanisms to sequentially effect advance of one of the carriages toward its broach ram portion of the column and retraction of the opposite carriage, andmeans independent of the motors for effecting synchronization of said opposite movements of the work holder carriages.

2. In a duplex broaching machine embodying a bed and a column rising from the bed having independent broach ram portions, work carriage guides on the bed individual to the respective ram portions, a work holding carriage slidably mounted on each of said guides for movement in a direction toward and from an opposed broach ram portion of the column, a toggle mechanism individual to each of the carriages having a portion pivoted to its associate carriage and a second portion pivoted to the bed, an individual hydraulic motor coupled with each toggle mechanism` for controlling the position of the toggle mechanism and thus of the associated carriage, means for effecting corresponding opposite actuations of the motor mechanisms to sequentially edect advance of one of the carriages toward its broach ram portion of the column and retraction of the opposite carriage, and means independent of the motors for eiecting synchronization of said opposite movements of the work holder carriages, said means iucluding a lever intermediately pivoted to the bed and having terminal sliding connection at each end with one of the toggle mechanisms.

3. In a duplex broaching machine embodying a bed and a column rising from the bed having independent broach ram portions, work carriage guides on the bed individual to the respective ram portions, a work holding carriage slidably mounted on each of said guides for movement in a direction toward and from an opposed broach ram portion of the column, a toggle mechanism individual to each of the carriages having a portion pivoted to its associate carriage and a second portion pivoted to the bed, an individual hydraulic motor coupled with each toggle mechanism for controlling the position of the toggle mechanism and thus of the associated carriage, means for effecting corresponding opposite actuations of the motor mechanisms' to sequentially effect advance of one of the carriages towards its broach ram portion of the column and retraction of the opposite carriage, and means independent of the motors for effecting synchronization of said opposite movements of the work holder carriages, said means including a lever intermediately pivoted to the bed and having terminal sliding connection at each end with one of the toggle mechanisms, each of said toggle mechanisms having a control slide actuated by its respective motor, said slide being formed with a guideway, and the intermediately pivu oted lever having shoe portions engaged and slidable within the respective guideways of the slides foreecting power interconnection of same.

4. In a broaching machine, the combination with a bed and a work carriage slidably mounted on the bed, of means for controlling the position of the carriage with respect to the bed including a rst link pivoted to the carriage, a second link pivoted to the bed, a pivot pin connecting the free ends of said links, an actuator link mounted on and depending frorn said pivot pin, a control slide carried by the vonage bed for movement in a direction parallel to the movement of the carriage, a power means for effecting reciprocation of the control slide, the length of the actuating link being such that when the pivotal connection to the slide underlies the supporting pivot for the link, said support pivot will be held with its axis substantially in the axial plane of the pivotal connections of the two rst-mentioned links to the bed and carriage respectively whereby reaction of the tooling operation against the work carriage will be transmitted in a substantially direct line through the links from the carriage to the bed.

5. In a broaching machine, the combination with a bed and a work carriage slidably mounted on the bed, of means for controlling the position of the carriage with respect to the bed including a rst link pivoted to the carriage, a second link pivoted to the bed, a pivot pin connecting the free ends of said links, an actuator link mounted on and depending from said pivot pin, a control slide carried by the bed for movement in a direction parallel to the movement of the carriage, a power means for effecting recipro cation of the control slide, the length of the actuating link being such that when the pivotal connection to the slide underlies the supporting pivot for the link, said support pivot will be held with its axis substantially in the axial plane of the pivotal connections of the two inst-mentioned links to the bed and carriage respectively whereby reaction of the tooling operation against the work carriage will be transmitted in a substantially direct line through the links from the carriage to the bed, said means for actuating the toggle operating slide including a lever intermediately pivoted to the bed having sliding connection at one end with the slide and a pitman coupling the other end of the lever with the power actuating means for the slide.

6. In a breaching machine, the combination with a bed and a work carriage slidably mounted on the bed, of means for controlling the position of the carriage with respect to the bed including a rst link pivoted to the carriage, a

second link p'ivoted to the bed, a pivot pin-connecting the free ends of said links, an actuator link mounted on and depending from said pivot pin, a control slide carried by the bed for movement in a direction parallel to the movement of the carriage, a power means for eiecting reciprocaton of the control slide, the length of the actuating link being such that when the pivotal connection to the slide underlies the supporting pivot for the link, said support pivot will be held with its axis substantially in the axial plane of the pivotal connections of the two rstmentioned links to the slide and carriage respectively whereby reaction of the tooling operation against the work carriage will be transmitted in a substantially direct line through the links from the carriage to the bed, said means for actuating the toggle operating slide including a lever intermediately pivoted to the bed having sliding connection at one end with the slide and a pitrnan coupling the other end of the lever with the power actuating means for the slide, a second similar carriage, toggle mechanism and control slide mounted on the bed for movements in directions corresponding to the movements of the rst set of parts, a power transmitting lever intermediately pivoted to the bed and having its ends extending in proximity to the respective cross slides, and means slidably interconnecting the ends of the lever with the respective cross slides, whereby application of power to one of the cross slides will react through the lever equally and positively to move the other cross slide and parts controlled thereby.

References Cited in the file of this patent UNITED STATES PATENTS 2,139,402 Cole Dec. 6, 1938 2,186,329 Harrington lan. 9, 1940 2,216,891 Nye Oct. 8, 1940 2,251,154 Nenninger et al July 29, 1941 2,323,463 Ferris July 6, 1943 

